Het volume van chirurgische ingrepen en de impact ervan op ... - KCE

134 Volume Outcome KCE reports 113
Table 6.6: CEA/CAS: Differences in case mix and outcomes by differences of
volume in centres
Tertiles based on
centre volume
N≤16 1631 All
Volume
N cases 411 882 2075 3368
N hospitals
Case Mix
39 36 35 110
Male % 64.2 68.1 66.0 66.3
Age
Mean 70.8 71.5 70.9 71.1
Std 9.0 9.0 9.1 9.0
Charlson index score Mean 1.3 1.4 1.3 1.4
Std 1.5 1.6 1.5 1.5
Charlson score ≥ 3 % 17.7 21.2 19.2 19.5
Modified Charlson index score
Mean 1.2 1.3 1.3 1.3
Std 1.4 1.6 1.5 1.5
Modified Charlson score ≥ 3 % 15.1 19.8 17.4 17.8
Co morbidity: diabetes 20.4 21.2 23.0 22.2
Co morbidity: renal disease 6.6 6.8 8.8 8.0
Severity index (APR-DRG)
1 25.8 24.3 28.5 27.1
2 55.0 58.0 54.7 55.6
3 17.3 15.3 15.1 15.4
4 1.9 2.4 1.6 1.9
LOS
Mean 8.2 7.8 7.5 7.6
Median 5.0 5.0 5.0 5.0
std 9.8 11.0 12.0 11.5
Outcomes
In-hospital mortality % 1.9 0.8 0.8 0.9
AMI % 0.7 0.8 0.6 0.7
CVA % 1.9 1.9 1.3 1.5
N =number
RELATION BETWEEN HOSPITAL VOLUME AND MORTALITY RATE
Table 6.7 presents the results of the logistic regression. Without adjustment for case
mix, an increase of 10% of volume of interventions is associated to a decrease of 4.5%
(95% CI -10.5%, 1.3%) in the odds of death. Taking into account the case mix, the
estimate of volume effect is rather similar (-5.3%; 95% CI -11.9%, 1.4%). This indicates
that case mix is not associated with hospital volume. Age and Charlson score are
positively associated with increased in-hospital mortality. A sensitivity analysis with the
adjustment based on the modified Charlson score (not including myocardial infarct and
cerebrovascular disease in the score) produced similar results. A second sensitivity
analysis based only on the volume of CEA interventions also produced a similar
estimate of the volume effect i.e. -6% (95% CI -12.4%, 0.5%).